Accumulate rhymes with:
emulate, formulate, reformulate, stimulate, articulate, calculate, circulate, coagulate, copulate, depopulate, emulate, formulate, innoculate, inoculate, manipulate, miscalculate, overregulate, populate, recalculate, reformulate, regulate, reregulate, speculate, stimulate, stipulate, strangulate, tabulate
Accumulate sounds like:
accumulated, assimilate, assimilated